Stryker flying wing re-design with foamboard

[ProfessorFate]

I've had a few strykers and wanted to make it over with foam board and aim for different characteristics. Strykers are nice easy goto foamies you can keep in your truck and fly after work somewhere. The foam blank can still be bought at Amazon or Ebay for $20, you add fins, motor etc. I just want one flies better
It will fly in any wind but stops penetrating and gets blown away after about 20 mph winds, and I did not try weighing it down with a heavy power system. But as stock, in some areas/conditions it nearly floats like a glider.

So I started looking at the arado 555 with goals of using a quieter 8" prop, 1250kv motor, 3s 2.6ah lipo.
Goals: better penetration and glide, better stability

The stryker has some funny angles that didn't make best use of the 20x30 inch foam board so you'll see in my drawing after some thought to arado leading edge I switched back to stryker flat form and only 2 places on the foam board to mark and cut straight lines.

7 and 4.5/16 Up on Left Side, 6 and 9/16 UP on the Right Side. See Drawings. And I start building on the bottom to to keep it flat except for shaping the LE bottom up a little for stability... a sharp edge makes some instability.

I'm referring to cutting out the Right Side. Mark a line from the Left 7 and 4.5/16" down to the bottom Right corner.
Go to Right side 6 and 9/16" mark and draw up to the top Left corner. This is the pattern for L and R.
So the one foam board is vertical, making 2 halves 40" wing span. Total needed is 4 sheets.

I could not find my wax paper, but after you apply gorilla glue you could put wax paper or teflon aluminum foil to make /shape glued joints as smooth fillets.

The stryker has 40 deg LE sweep and this one has 50 degree LE sweep and I'm trying all I can to make the top fast surface smooth to increase lift, including I might put servo link and control horn on bottom. Bernoulie lift likes the top surface as smooth as possible and wind passes over it fastest, creating that lower pressure that Pulls the wing up along with the higher different pressure Push the wing up.

I'm using regular gorilla glue as much as possible and Ross foam board because their paper sticks the best to the foam, dtfb just peals off too easy. Just in case I also cut paper out in small spots to help glue bond to everything. The wood is 2.7mm underlayment sheets 4x8 cut down to 1x4 foot, great savings much cheaper than midwest lite ply.

Near the center stryker measured 1.25 inches so all those measures on the sheet are the inside space 7/8 plus 3/8 being 2 foam sheets giving 1.25 inches thickness working outboard called in 8ths only

That wide blue foam holds the edge to glue the foam board. I'll make more in decreasing sizes outboard to tips and glue the foam sheet on top of these. The smaller ribs might be glued with a little extra height so they can measured compared and sanded. The outside tips max at 1/8" inside.


So with current airframe, lipo, controller and motor, the weight is 26 oz. The last Stryker, F27Q weighed 30 oz, I might be a few ounces over

 

[ProfessorFate]

I may have the confirmation I want, the Stryker and FT Spear have 40 degree LE sweep and I'm doing 50 degrees favoring more stability, penetration, hopefully lift if I make the top smoother. Now the last detail if I wanted to switch, center fins or wing tip fins.

 

[ProfessorFate]

10.5oz body... plus motor, controller, and lipo 27oz

I like the look of the Stryker but tip fins may reduce vortex drag at tips and channel the top lifting surface.
Wish I could put the servo horns on the bottom without risking damage

All those numbers are inside space in eighths. Changed my mind and measures a few times and forgot to tear away glued sections of paper to mix it up both ways. But this is Ross foam board, the paper sticks lots better than dtfb.

 

[ProfessorFate]

Yesterday was "National Kitten Day". I have one of these earlier family members one generation back, now young female. This guy hisses at me like his brother/sis.

The orange one on the work bench, mine. Sidney Poitier the black cat from 2016 still with me, black cats are healthy and always have a cool mood. And so, Black Cats get a much un-deserved bad rep as the witches cat or other superstitions. Less susceptible to feline lukemia.

I caught the young Sidney at just the right time. How low would he go? See this is a gif file I had much fun with! It's like he's saying ... "What are you looking at"?!!!

The young kittens and children... have no inhibitions about what is correct and will tell you the truth, not what you want to hear.

I layed whole foam board over frame, clamped it to LE and marked it leaving some random at the back.
Curled much more till I knew it would glue down without deforming bottom. Remember I simplified using one whole sheet and only 2 cut marks. That center section took off enough along 30 inch length to allow over 2 inches random and I only need about 1.5 inches for the elevons.

Meow!

 

[ProfessorFate]

All that wing without rudders looks so good for a lifting surface, I'm putting the rudders on the tips. Have to smooth LE with a grinder or file. See how I sealed front and back edges by folding paper over gorilla glue? So far nothing but gorilla glue.

18oz frame 36oz or 2#4oz with motor, controller, lipo. So I'm hoping there is a significant difference in greater lift, putting the vertical stabs on the tips. This last F27Q Stryker listed rtf weight as 30 oz. I have to get greater lift and penetration to make up for the extra weight.

 

[ProfessorFate]

Here's another prop jet really grabs me. The edges have been cleaned up, 1680 x 1050 looks good as desktop but imagine it flying and gliding.

I saved the paper around edges to fold over with gorilla glue. Smoothed with a grinder and thin 4.5 inch new cutoff disk. There's more to be done.

There were some moments of doubt because of the weight, but I have to finish and see. The paper inside could have been removed to save weight and I just don't have anymore light controllers and motors.

But... I wound this motor iFlight 2814 8t 20awg for 22 amps hpdlrk wye 1200 kv weighs 4.5 oz 3s using an apc 8x6

Do you know of a good tough but sandable filler, not CA + baking soda, that would be brittle, right? Just put more gorilla glue over and sand?

I want to cook some hamburger on the smoker. Meat meat meat, pork ribs, briskit, pork butt! That mix 4 habanero and can of tomato sauce with hamburger was good. Maybe try smoke 1.5 hours, finish moist in dutch oven 250 degrees.
You cannot see it, but, I put 2 inch pipe insulation around the fire box where most heat loss is (closed in welded with 14 gage sheet). It really makes a huge difference, the table used to get
so hot it melted my thermal monitor.

 

[ProfessorFate]

Back by the TE elevon, the space to put a servo is very shallow and I want as much of that 3/16 inch top of airfoil as I can get. I thought of teflon Al foil, other things, then just put the gorilla glue, kept cool inside and shaped with scraps then fingers. Worked good that way. A socket of paper and gorilla glue for a 9 gram servo.

Pork Ribs... great if you smoke them right.

Now I need to go cook some more

 

[ProfessorFate]

All the Strykers have the same area and shape, but the last F27Q weighed 30oz.
So seeing the difference in size area and weight of body, 2 servos, motor, controller, 2.6ah lipo is 34 oz ... needs fins, motor mount and cockpit cover and paint

The servos are mounted on paper with gorilla glue

 

[ProfessorFate]

Got a little discouraged about Weight and Wing Load. Calculated area of original Stryker, appears more like 393 inch^2 and 2.73 ft^2 at 22oz rtf 8.06 oz/ft^2
My Stryker/Arado Area is 4.09722 ft^2 WL 9 oz est weighed with motor, prop, controller, and 2.7 AH Lipo so it's looking good

Pushers look good, I bought these motors un-wound new, and this one wound 8 turns of 20 ga for 22 amps limit half parallel dlrk wye and in some cases they give more thrust for less power than the common mfrs delta terminated motors.

The only part has hot glue are the hinges.
To have a foamy you can keep in the car even in Hot South Texas sun, has anyone ever tried Silicone for hinges instead of hot glue? Silicone could be massaged into both elevon side and body side on the bottom. I'm using that walmart foam board sticks better to the foam. Would silicone debond paper from foam? Guess I can test sometime. Past the flexy hinge part, spots could be drilled or cut open and glued with gorilla glue as a stop. And if a thin layer were massaged into top of paper hinge I do not think it would ever break or wear out.

 

[philgabanski]

Ever since I broke my first brushed motor Stryker, I've been replicating that awesome cranked wing design!!! The Balsa one in blue I made 15 years ago. The red one made of insulation foam wire cut and sanded around 7 years ago! The other two about 4 and 2 years ago from foamboard!!! They are smaller! Just love the Stryker!!!!

 

[ProfessorFate]

Hey what a surprise! Hi Phil ... I like your picture and story of Your strykers over the years
Over the years I have used the Strykers figures as an example and it sure is nice to have something like this ready in your truck after work. If you have a thread on building these I want to look that up and see how you ran the linkage straight... with ball links?

Tonight I came back to this so I might attach the fins, arrange things to hold hardware, cover and test fly.
The ez fun part is the test and I wondered 8x6, 3s, how much current, how much thrust?
I see a lot of people just say they ran some maximum figure of current thru their motor.
Well here I did this this too but already with two test points that directly involve thrust and current.

Few years ago I came up with this linear estimation program... so many mfrs testing motors only give wot figures.
I think it's important to know what the strain on the motor means for the test. I watch out using those figures, like a small motor with a hi kv trying to swing the largest prop and almost red-lining.

My motor 2214 -- 1200kv used 26.8A WOT on a fresh 2.6AH lipo, motors I picked for test points ... the apc 8x6 was an ez prop load and they maxed out from kv ... just not able to run faster, not stress from the load

Here's a 7 inch base fin 5 inches tall leaned over at 45 degrees wanting to make Stryker have some 1959 Cadillac Eldorado Fins... yehahhh! It's 300 dpi and please use if you like, put up a picture! Office Depot will print on heavy card stock 8.5 x 11 inch max like about 100# paper 1st print cost $4 each additional $1 each tot cost $7. Phil or others what do you think of proportions on the fin pic, no caddy has a config like this anyway.... light too big or look OK? Got another I should make pics for print to have pilots on the Savage Bobber, wing adapter for Apprentice wing, but I want to build a wing for it foam or wood, about ready, pics are not too scale to print. If Depot can print straight over the page needs no alteration and they won't mess it up. I think I'll move fin away from boarder so it won't make problem for printing.

Here's motor tests, and I wrote this pgm for linear thrust est terms X and Y rpm and thrust, but I did a substitution using current and thrust since it's just ratios and estimation... no problem. Thrust est came to 39.5oz, current was a little higher but with a quick drop I didn't count. My current tester is 150A max... it's all in the pics.

Look over see if you follow this algorithm I programmed into HP48gx, it uses RPN form rather than algebraic, that HPs over 20 yrs old

 

[ProfessorFate]

There is another Cadillac that has a tail light like this, so how do you like THIS fin for the Stryker? This is ready to print same size 300 dpi centered on 8.5x11 it's 7 inches top and bottom and 5 inches high. I had to get this done before putting the foamboard fins on. Now to secure battery, radio, and make the cover and attach the fins, test fly and print the four fins to apply.

 

[ProfessorFate]

Both are on 8.5 x 11 size 7 inch base, other better spacing from edges 300 dpi. I think this might be the fin to use. Hatch, battery tied down, radio secured too and I'm test flying.

 

[momopilots]

I bought a SWAN K1 Voyager drone from HEQ. It is a VTOL drone. I think this fix wing drone has a long battery life, about 50 minutes, and the assembly process was simple and I had it installed in no time, and the video/image is also clear.

 

[ProfessorFate]

Hi momopilots
Something interesting about a warbird with 2 motors, you can get MORE thrust for LESS power ( guy works in flite test shop said you can put two motors on one controller ). The 24oz run uses 5.9 amps, now 48oz uses 20 amps but of course at the same 35mph but 3# thrust for 11.8 amps instead of 20 amps. I wish more mfrs tested motors like I do at different thrust levels. The thrust was inferred by various rpm to thrust charts but voltage and current and rpm were exactly measured. Thought yours only used 2, but saw the other two like sleeping bowling pins. I think this is the reason why you don't use that much power, and all motor/prop combos are different. It sure has been fun and interesting winding motors and learning.

Here's the time I figured how to make the starts and stops all go the same way. The advantage to use is the first coil comes out neat tight and smaller, so I put the messy 2nd coil on a strand between 2 small skinny coils then try my best to stuff the 2nd coil between and take what I can get. I take it even if I miss a turn or 2, they still work just fine... makes the kv go higher than planned tho. Wind 1 then 3 then stuff the 2nd one in between. Circles mean wind counterclockwise. One strand winds 2 stator heads.

This was interesting to figure out, everywhere the arrow pointed backwards, that was one out-of-phase change that required another change so it would right the change and the motor would work. The black minimalist wind diagram is the new one favored distributes the coils -- skinny-- fat ending -- skinny -- fat ending -- ... I sure enjoyed this, did a test wind w small wire and it worked right the first time!

A few yrs ago made these A123 LIFE 12 volt 2.2 AH battery packs, tested to hold ~ 10 amps this gives 32oz thrust at 107 watts ran good n strong for 13 minutes. I need to use this on some light foam 60" WS airplane. They're little heavy and don't work good in smaller airplanes. By this motor 11 amps would give 48 oz thrust at 35mph.

 

[JetCrafts]

i didnt understand a word
probably because I have an iq of 2

 

[ProfessorFate]

Oh Hi Jet ... Leonard
Go easy on yourself. I've been rewinding motors 4 yrs now. One day said hey I gotta look at these as circuits since I am a technician. Was just following the known patterns. Started figuring out how Manual got #s from that spread sheet for turns that determined rpms per volt... kv. Then Manual n Trog came up w and adj coil wind but see they had it where the big fat coils ended up next to each other. You always want to do all you can to get as much copper in a wind so I thought in this way of algebra declaring what you want an adjusting the equation. Well get pattern fat n skinny, fat skinny by making all arrows point same way. Where I changed the arrows direction, another change was needed to get the phases or magnetic orientation right. Hey I didn't have to use any fancy physics or right hand rule, the only thing to change was the wind directions on the affected strands. It's like amplifiers, one stage inverts and your signal is 180 out of phase, get it back by adding another phase, see. I felt such immense gratification with the soln, I wanted to share it. Thrilled it worked first time on the test wind. The Half Parallel dLRK adjacent coil wind w coils evenly distributed. Wind the odds first and stuff the evens in however they will fit. Even had nice symmetry where you just put the odds to the bundle for a wye termination. Well... I just got curious about how these things worked.

Did you see, 7 yrs ago, I guess, I had a real good time figuring that linear estimation algorithm and then programming it. Give it 2 x/y points that makes a line with a slope and then I use to find how many rpms for an even 3 # thrust. This time I estimated by how much current, the amount of thrust I got 39.5 oz. Mfrs only give WOT test figs.

I'm obsessed with motors! Found a vcr in the garbage and did a couple test winds on it... fun.

 

[philgabanski]

Here is the build log for my XPS cut Stryker. This particular one was scaled up in size and since this thread has had a major power upgrade to 4S! 1450kv with a JSF 7x6 high flow prop.

Recreating an old love (again!) Scratch build F-27

It was the plane I learnt to fly with, an f-27b model complete with brushed motor. It could barley climb and had many many hard landings, and goal post encounters. One day I blew up the battery so sought to upgrade. After some research bought brushless motor, 3s lipo, servos and esc and brought...

forum.flitetest.com

I'll get some footage of how it flies now!

 

[philgabanski]

Found the smaller one too

Cranked Delta Wing park jet (Curved foam board Aerofoil)

So a few hours with some 5mm XPS foam sheets from Hobbyking and this happened! I have seen the versa wing, and have a love for the double delta wing (or a leading edge wing extension LERX) and thought that looks like an awesome idea. I also learned to fly 10 years ago on the original F-27...

forum.flitetest.com